1. Field of the Invention
This invention relates to a method of fabricating a semiconductor device and in particular to a process of manufacturing a double diffused metal oxide semiconductor (DMOS) transistor.
2. Description of the Prior Art
The tendency of the semiconductor technology is to make power semiconductor devices more compact and with higher density. To this end, it has been found necessary to provide critical alignments of very small dimensional geometries of the conductive regions of the device. Therefore, additional masking steps with critical tight specifications have been used, thereby adding to the time and expense of manufacture, as well as reducing the yield if tight dimensional tolerances are not substantially met. In the manufacture of DMOS transistors, for example, six or more masking steps are required in order to satisfy the high resolution requirements.